1. Field of Invention
The present invention concerns mononuclearly filled microcapsules, foodstuff compositions and other articles which include one or more mononuclearly filled microcapsules as well as processes for production of mononuclearly filled microcapsules.
2. Related Art of the Invention
In the field of encapsulation of active ingredients (active substances on or in carrier materials) there are frequently problems in particular in the field of foodstuff technology, for example, the incomplete immobilization of the active substances on or, as the case may be, in the carrier material.
In the field of the systems for functionalizing, in particular the release (freeing) of active ingredients (active substances) from out of the carrier materials, these types of problems frequently result from an inappropriate, that is, either incomplete or however also possibly early or delayed, release of the active substance from out of its carrier material.
Although in certain applications, in particular in pharmacology, agrarian chemicals and cosmetics, active substance-carrier material combinations have already been found, which meet the requirements both with respect to the encapsulation efficiency as well as with respect to the requirements in practice regarding releasing, nevertheless in all industrial nations great investment has been made in searching for systems which in certain areas of application make possible a situation-appropriate release of active substances out of a carrier material.
Despite extensive efforts, until now only relatively few functioning systems have been discovered for encapsulation and functionalizing of ingredients in the area of foodstuff technology and foodstuff chemistry. This is due in part to the limited approval of possible carrier materials for the respective ingredients. In particular however problems occur with those types of flavors or fragrances, of which the composition is complex, which is expressed in the diversity of the volatilities and the range of polarity of the individual aroma components of the fragrance or flavor as well as in the sensitivity of one or more of the fragrance or flavor components to external influences.
From the highly developed field of literature regarding active ingredient—release systems, reference can be made to the following documents:
Brandau, Thorstein; Pharma+Food March 2001, 8-12:
In this document microencapsulated active substances and microspheres are described in pharmaceutical and cosmetic applications. As processes for production of microspheres, the so-called microsphere process is specified, which results in highly spherical granules (solid spheres) with monomodal grain size distribution. The one or more active substance is evenly distributed throughout the entire sphere, in a matrix of the carrier material. Further, microcapsules are described, for the production of which a liquid or liquefied active substance is embedded in a solid shell.
WO 93/02785:
This document discloses a process for production of alginate spheres (solid spheres) from droplets of an alginate solution, wherein droplets are released from a nozzle and allowed to drop into an ion solution, which solidifies them. The alginate solution is rendered into droplets by oscillation excitation. Mononuclearly filled capsules are not disclosed.
WO 98/15191:
This document discloses a process for production of spheres (beads) as nutrient—additives, wherein these solid spheres are loaded with at least one active ingredient selected from the group of flavor substances. Mononuclearly filled capsules are not disclosed. Data or information regarding ingredients from the field of flavors or fragrances, in particular water insoluble flavors or fragrances, and technical advantages of the carrier material with respect to heat stability are disclosed, wherein however the release is not spontaneous, but rather occurs continuously during manufacture or preparation, in particular however during storage of the nutrients.
WO 98/15192:
This document discloses a process for production of spheres (beads) as nutrient—additive, wherein in a finishing process step previously manufactured water insoluble spheres (solid balls) are retroactively or subsequently loaded with at least one active, amphiphilic ingredient.
The encapsulation of taste substances (flavor substances) in spheres (beads) brings about that the flavor substances possess an improved thermal stability and water insolubility during the further processing of the beads. The flavor release is however not instantaneous during chewing or breaking of the bead-particles in the mouth, but rather is based upon a continuous and slow process of diffusion of active flavor components out of the encapsulated material into the foodstuff matrix. This is described in particular in WO 98/15191 and in WO 98/15192.
EP 0 513 603 B1:
This document discloses a process for production of seamless capsules, in which a fluid stream is blown out of multiple nozzles for the formation of capsules, so that droplets are formed, which are then brought into contact with a hardening fluid, in order to produce the seamless capsules. These seamless capsules are mononuclearly filled. Information regarding capsule materials is not provided. Information regarding possible ingredients or possible technical advantages of the shell materials in practical applications are likewise not provided.
JP 11155480 A describes microcapsules filled with oily aromatic ingredients, which are obtained by reaction of polysaccharides such as alginates with calcium or metal ions and which are heat and water resistant. The shells of the described capsules exhibit however a high water proportion of greater than 90 wt. %, based upon the capsule shell.
JP 09065853 A describes a microcapsule filled with the flavor substance wasabi which is formed with sodium alginate and a polysaccharide as form and stabilizing adjuvant by means of a two-fluid nozzle and is hardened with calcium chloride. However here the hardened capsule shell material possesses a very high water content, greatly above 50 wt. %.
A high water content in the capsule is very disadvantageous for the performance of a capsule and in particular for its heat stability and its flavor retention value, as has been determined by various experiments within the framework of the present invention.